any happy FMF Q4 owners?

23 replies to this topic
  • SparksXR426

Posted October 26, 2009 - 07:41 PM


FMF is now making both a SS and Ti mega-bomb. On their website it still says Ti only but if you bring up the application of your bike it then shows options for both.

We are involved in lots of land use battles up here and I really need to put my money where my mouth is so to speak, so I ordered what I think is going to be the quietest system possible...FMF Q4 and mega-bomb header.

Oddly enough, the SS mega-bomb is already on back order so I guess I will have to run the Q4 with my stock header until it ships.

Anybody have jetting hints for the Q4 and mega-bomb? I have heard that I will need to go a size richer on the pilot and one or two richer on the main but I would like some first hand knowledge if its out there.

Cant be much help with the mega bomb but I have the Q-4 slip on. I ride sea level to about 3000 feet and run stock jetting, cleaning it up with the fuel screw. Thats with the sparky out. Running the sparky makes a huge difference, very quiet and the power delivery is softer than stock, especially on top. Interested to see what the header does but with the slip on alone I would say its too rich already with sparky in and stock jetting. I have a sound meter I use for work and intend to check the db level but this pipe is QUIET. :bonk: My neighbour has the same bike with a full Pro Circuit system and can bust windows at 100 yards.

  • jasonlion54

Posted October 27, 2009 - 08:59 AM


I didn't change my jetting at all when I installed my Megabomb and Q4 pipe. And I wish I had gone with the SS, since my Ti header is in the freezer at this very moment.:bonk:

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  • HwyChile

Posted October 27, 2009 - 09:28 AM


So far about the only person I've seen here who has a Q4 exhaust (02YZ426?) has had trouble with it.

Has anybody got one that is holding up well?

I have read of some durabilty problems with FMF exhausts in general. That's why I did not buy one. Of course, I have read of the same types of problems for some of the other big names.

I thought you were running a Jardine exhaust (their quiet exhaust). Are you not happy with it?

I am running a Leo Vince X3 exhaust with a Pro Circuit stainless header and it is quiet compared to some exhausts, but it is too new to know how durable it will be. I do not know how it stacks up to the FMF quiet exhausts for quietness. My bike is a WR250F.

  • Aka.Goose

Posted October 28, 2009 - 05:01 PM


Hey KAS, I've been happy with my megabomb/Q4 ti setup...Put my bike through cartwheels just about every outing...No issues yet...Smooth power with 165/45 jetting...Just doesn't wake the bottom end up the way most aftermarket pipes do...But it is crazy quiet, and smooth, and the durability/quality seem just fine...

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